title: [Causes and prevention of "black line" in porcelain-fused-to-metal crown margins].
mesh_terms: D003442:Crowns / Q000009:adverse effects*; D003776:Dental Porcelain; D006801:Humans; D016876:Metal Ceramic Alloys
chemical_list: D016876:Metal Ceramic Alloys; D003776:Dental Porcelain